The present invention relates to a method and a system for management to manufacturing semiconductor devices, and more particularly to a manufacturing management method and a manufacturing management system provided in a manufacturing factory for managing manufacturing processes for manufacturing industrial products, wherein batch-processes in lot-units are implemented.
In a semiconductor manufacturing factory for manufacturing semiconductor devices, plural semiconductor wafers are accommodated as one lot in a carriage, and batch processes for the plural semiconductor wafers are made in the lot unit. Photo-lithography processes are typical processes for manufacturing the semiconductor devices. In accordance with the photo-lithography processes, a photo-resist film is applied on each of the semiconductor wafers, and an exposure process is carried out to the photo-resist film and a subsequent development is made to form a photo-resist pattern over each of the semiconductor wafers. Each of the semiconductor wafers is then subjected to a dry etching by use of the photo-resist pattern as a mask. The above sequential processes are single wafer processes for processing individual single semiconductor wafers sequentially. By contrast, the deposition processes such as the chemical vapor deposition processes and the heat treatment such as annealing for causing a diffusion of impurity ion-implanted are the batch processes for processing the plural semiconductor wafers concurrently. The manufacturing processes for the semiconductor devices include both the single wafer processes and the batch-processes. It is, therefore, possible that the plural semiconductor wafers are sequentially subjected to the single wafer processes before the sequentially processed semiconductor wafers are then concurrently subjected to the batch process. It is also possible that the plural semiconductor wafers are concurrently subjected to the batch process before the batch-processes plural semiconductor wafers are sequentially subjected to the single wafer processes. It is also possible that the same process such as the diffusion process is carried out in plural times on different steps in the sequential manufacturing processes. This means it possible that the plural semiconductor wafers of one lot and the other plural semiconductor wafers of different lot are concurrently subjected to the batch-process such as the diffusion process or the chemical vapor deposition process.
FIG. 1 is a schematic diagram illustrative of the conventional facilities on the semiconductor manufacturing line in the semiconductor manufacturing factory. The conventional facilities comprise a circulated carrier carriage rail 501 on which a plurality of carrier carriage 500 is moved, and a plurality of blocks BL1, BL2, BL3, BL4, BL5, BL6, BL7 and BL8. Each of the blocks BL1, BL2, BL3, BL4, BL5, BL6, BL7 and BL8 has plural and various manufacturing apparatus 300 for performing predetermined manufacturing processes to the semiconductor wafers and two wafer stokers 200 for stocking the plural semiconductor wafers. Automatic carrier cars 400 are moved in each of the blocks BL1, BL2, BL3, BL4, BL5, BL6, BL7 and BL8 for carrying the plural semiconductor wafers in one or more lot units among the plural and various manufacturing apparatus 300. The automatic carrier cars 400 picks up the one or more unprocessed wafer lots from the stoker 200 to carry the same to the individual manufacturing apparatus 300 for the individual processes. Further, the automatic carrier cars 400 picks up the one or more processed wafer lots from the individual manufacturing apparatus 300 to carry the same to the stoker 200 for accommodating the same therein. Each of the stokers 200 in each of the blocks BL1, BL2, BL3, BL4, BL5, BL6, BL7 and BL8 is connected with the circulated carrier carriage rail 501 on which the carrier carriages 500 are moved among the individual blocks BL1, BL2, BL3, BL4, BL5, BL6, BL7 and BL8 for carrying the wafer lots from the stokers of one block to other stokers of different block to allow the processed wafer lots in the one block to be further subjected to the different processes in the different blocks.
The above various semiconductor manufacturing apparatus are classified into two types, for example, the batch-processing apparatus and the single-wafer-processing apparatus. In each of the blocks BL1, BL2, BL3, BL4, BL5, BL6, BL7 and BL8, the one or more wafer lots are picked up by the automatic carrier cars 400 from the stoker 200 and then carried into the semiconductor manufacturing apparatus in the same block. It is necessary for the semiconductor manufacturing system to manage the processings of the wafer lots, for which purposes, a host computer is provided for controlling the stokers 200, the individual manufacturing apparatuses 300 and the automatic carrier cars 400. Namely, the management is made mainly by the host computer.
FIG. 2 is a schematic view illustrative of a conventional management method, in accordance with which the host computer controls the stokers, the individual manufacturing apparatuses and the automatic carrier cars. FIG. 3 is a timing chart illustrative of operations of the conventional management method, in accordance with which the host computer controls the stokers, the individual manufacturing apparatuses and the automatic carrier cars. It is assumed that a manufacturing apparatus 301(300) be the batch-processing apparatus which is capable of batch-processing the plural wafer lots. A maximum batch lot number is 4. Namely, the manufacturing apparatus 301(300) is capable of batch-processing four wafer lots at its maximum. The manufacturing apparatus 301(300) has an internal tray 30 which is divided into a first tray 31 for storing wafer lots and a second ray 32 for storing other wafer lots. The wafer lots stored in the first tray 31 and the other wafer lots stored in the second ray 32 are alternately subjected to the batch-process. Each of the first and second trays 31 and 32 has a capacity of storing the four wafer lots as the maximum lot number.
In a first step S501, after the current batch-process has been completed by the manufacturing apparatus 301(300), then the processed wafer lots are returned to carriers of the second tray 32 and further the automatic carrier car 400 carries the processed wafer lots into the stoker 200. The wafer lots stored in the first tray 31 are carried to a processor not illustrated, and then an loading request for carrying the wafer lots to be subjected to the batch-processing from the stoker 200 to the manufacturing apparatus 301(300) is sent to the host computer 100.
In a second step S502, the host computer 100 determines a single wafer lot in accordance with the dispatch rule. The host computer 100 further retrieves the determined single wafer lot and other wafer lots which are allowable to be batch-processed to form a single batch unit. If the number of the wafer lots in the batch unit is less than the maximum batch number, then the extent of the retrieval is expanded to the other stokers of the other blocks, so that the host computer 100 further retrieves the one or more wafer lots which are allowable to be batch-processed. The retrieved wafer lots are then carried by the carrier carriage to the subjected block to enable formation of the batch of the maximum number of the wafer lots. After the batch has been established, the host computer 100 sends the manufacturing apparatus 301(300) a notice of the objected wafer lots to be batch-processed.
In a third step S503, upon receipt of the notice of the objected wafer lots to be batch-processed, the manufacturing apparatus 301(300) sends the host computer 100 a load request for loading the wafer lots in the batch unit.
In a fourth step S504, upon receipt of the load request, the host computer 100 controls the automatic carrier car 400 so that the automatic carrier car 400 carries the objected wafer lots from the stoker 200 to the manufacturing apparatus 301(300), and the wafer lots are then stored in the second tray 32 in the manufacturing apparatus 301(300). As described above, the number of the wafer lots in the batch unit is 4. The automatic carrier car 400 carries two wafer lots at one time. Namely, the automatic carrier car 400 carries the four wafer lots by two carrying operations. As shown in FIG. 3, if three wafer lots xe2x80x9cAxe2x80x9d, xe2x80x9cBxe2x80x9d, and xe2x80x9cCxe2x80x9d are retrieved to form the single batch-unit, then the automatic carrier car 400 carries the two wafer lots xe2x80x9cAxe2x80x9d and xe2x80x9cBxe2x80x9d by the first carrying operation and then the automatic carrier car 400 carries the remaining wafer lot xe2x80x9cCxe2x80x9d by the second carrying operation. The load requests are sent from the manufacturing apparatus 301(300) to the host computer 100 every times when the automatic carrier car 400 carries the wafer lots.
In a fifth step S505, after all of the wafer lots forming the batch-unit have been accommodated or stored in the second tray 32 in the manufacturing apparatus 301(300), then the manufacturing apparatus 301(300) sends the host computer 100 an input inhibiting request, whereby the operations for storing the wafer lots are finished.
To carry the wafer lots from the stoker 200, the host computer 100 sends the stoker 200 a put-out instruction in a step S506. After the wafer lots have been put out of the stoker 200, the stoker 200 sends the host computer a put-out report in a step S507.
In accordance with the conventional managing system, the next wafer lots to be batch-processed in the next cycle are stored in the second tray in the manufacturing apparatus and then the manufacturing apparatus transmits the input inhibiting request to the host computer to finish the storage operations, before the manufacturing apparatus performing the batch-process to those stored wafer lots forming the batch-unit. For this reason, once the storage operations of the wafer lots to be subjected to the next time batch-processing have been finished, it is impossible to add any additional wafer lot to the stored wafer lots in the second tray of the manufacturing apparatus even the additional wafer lot allowable to be processed in the same batch-processing could have been carried into the stoker from the other manufacturing apparatus in the same block or the other manufacturing apparatus in the other block. If the number of the wafer lots forming the batch-unit does not reach the maximum wafer lot number, and if any new wafer lot is allowable to be subjected to the same batch-process, then it is, however, impossible to add the new wafer lot to the wafer lots forming the batch-unit. Namely, the new wafer lot has to be unwillingly subjected to the further later batch-process. This reduces the batch filling rate and also the throughput of all of the manufacturing apparatuses.
In Japanese laid-open patent publication No. 3-23621, it is disclosed that the control unit decides the maximum lot number of the batch-unit and previously confirm individual priorities of the transfer states, the process conditions, the process time periods of the individual samples, so as to order the individual samples in the priority order. If the lot number reaches the maximum lot number, then the batch of the lots is formed and inputted into the manufacturing apparatus. If the lot number reaches the maximum lot number, then it is verified whether or not it is possible to add a sample to the batch on the basis of an expected arrival time of the sample from the transfer state, the processing time period and the priority order. If possible, the sample is added to the batch for subsequent input into the manufacturing apparatus to improve the efficiency of the batch-processing.
The above conventional technique disclosed in the Japanese publication utilizes the control unit to confirm the wafer processing states of the individual manufacturing apparatus and also the wafer states for subsequent operations of transferring the wafers to be processed to the individual manufacturing apparatus. In case that the system includes many manufacturing apparatuses and many stokers, the host computer grasps all states of the wafer lots of the individual manufacturing apparatuses and the individual stokers, for which reason the host computer has a tremendously large load. The host computer is needed to have a large capacity and a high speed performance. The necessary programs of the host computer is also complicated. The load for maintenance to the host computer is large.
In Japanese laid-open patent publication No. 8-236413, it is disclosed that a central unit is provided for the plural manufacturing apparatuses and trays, wherein the central unit comprises a progress-state comparing and calculating unit, a manufacturing apparatus state monitoring unit, a stock management unit, and a tray control unit. The central unit monitors all of the manufacturing apparatuses and decides the wafers to be processes at the next time on the basis of the timing signals, and then the automatic retrieval of the wafers as decided is made for subsequent processing the decided wafers by the manufacturing apparatus. The retrieval to the wafers is made before the timing of processings the wafers in the manufacturing apparatuses to improve the efficiency of the wafer processings.
The above conventional technique disclosed in the Japanese publication utilizes the central unit to confirm the wafer processing states of the individual manufacturing apparatus and also the wafer states for subsequent operations of transferring the wafers to be processed to the individual manufacturing apparatus. In case that the system includes many manufacturing apparatuses and many stokers, the host computer grasps all states of the wafer lots of the individual manufacturing apparatuses and the individual stokers, for which reason the host computer has a tremendously large load. The host computer is needed to have a large capacity and a high speed performance. The necessary programs of the host computer is also complicated. The load for maintenance to the host computer is large.
In the above circumstances, it had been required to develop a novel system and method of maintenance to manufacturing semiconductor devices free from the above problem.
Accordingly, it is an object of the present invention to provide a novel manufacturing maintenance system having many manufacturing apparatus and stokers free from the above problems.
It is a further object of the present invention to provide a novel manufacturing maintenance system having many manufacturing apparatus and stokers, which improves efficiency in batch-processing of the wafers without increasing the load to the host computer.
It is a still further object of the present invention to provide a novel manufacturing maintenance system having many manufacturing apparatus and stokers, which improves efficiency in batch-processing of the wafers without complicated programs for the host computer.
It is yet a further object of the present invention to provide a novel manufacturing maintenance method applied to the manufacturing maintenance system having many manufacturing apparatus and stokers free from the above problems.
It is a further object of the present invention to provide a novel manufacturing maintenance method applied to the manufacturing maintenance system having many manufacturing apparatus and stokers, which improves efficiency in batch-processing of the wafers without increasing the load to the host computer.
It is a still further object of the present invention to provide a novel manufacturing maintenance method applied to the manufacturing maintenance system having many manufacturing apparatus and stokers, which improves efficiency in batch-processing of the wafers without complicated programs for the host computer.
The present invention provides a system for managing a manufacturing processes including at least a batch-process for a batch which comprises plural product lots. The system comprises: a host computer; at least a batch-manufacturing apparatus for carrying out a batch-process under control of the host computer; at least a stoker for storing the plural product lots; at least a carrier for carrying the plural product lots between the batch-manufacturing apparatus and the stoker under control of the host computer, wherein a loading request is transferred from the batch-manufacturing apparatus to a host computer, and the host computer retrieves batch-processable product lots to form a batch of plural batch-processable product lots, and the batch-manufacturing apparatus verifies whether or not a lot number of the batch reaches a predetermined maximum batch-lot number, and an additional loading request is sent from the batch-manufacturing apparatus to the host computer, and the host computer is further retrieved whether or not any further additional batch-processable product lot is present, and the additional batch-processable product lot is carried to the batch-manufacturing apparatus to add the additional batch-processable product lot to the batch.
The above and other objects, features and advantages of the present invention will be apparent from the following descriptions.